<form method="POST" action="recherche.php">
    <input type="text" name="mot" size="27">&nbsp;&nbsp;<input type="submit" value="Rechercher"><br />
    <input type="radio" name="type" value="2" <?php echo check(2,$type,'check'); ?>> Eau douce
    <input type="radio" name="type" value="1" <?php echo check(1,$type,'check'); ?>> Eau Mer
    <input type="radio" name="type" value="3" <?php echo check(3,$type,'check'); ?>> Eau froide
    <input type="radio" name="type" value="0" <?php echo check(0,$type,'check'); ?>> Tout
</form>